Jump to content

Need help in speeding up this script as it has 45,000 co ordiantes

DanielStead

By DanielStead
in PHP Coding Help

 Share

Recommended Posts

DanielStead Newbie

DanielStead

Posted
Posted
I have a script that basicallydraws around each township on a map and makes each township linkable in total i have about 498 townships and a total of 44,337 co ordiantes. the script is below and basicallys has 2 loops one to make the sections of the area map linkable and one to actually draw the round the townships. the reason for this is that we have four processes to run on each township so we will fill the township with a different colour depending on what processes have been run on the township.

Here is the code

[!--quoteo--][div class=\'quotetop\']QUOTE[/div][div class=\'quotemain\'][!--quotec--]<?php
session_start();
require_once("include/check_login.php");
require_once("include/database.php");
require_once("include/functions.php");
?>


<html>
<head>
<title>Cheshire County Council (v0.1) (v0.1)</title>
<script type="text/javascript" src="js/wz_jsgraphics.js"></script>
<link href="css/cheshire.css" rel="stylesheet" type="text/css">
<style type="text/css">
<!--
.style1 {color: #0000CC}
-->
</style>

<body>
<?php
echo " <div class=\"mapcontainer\" style=\"width:1500px\" style=\"height:1069px\">\n";

echo " <img src=\"images/CheshireMap_Final_Rect.jpg\" border=\"0\" usemap=\"ParishMap\" id=\"anotherCanvas\">\n";
echo " <map name=\"ParishMap\">\n";

$sql = "SELECT Distinct Parish, Township FROM CheshirePolygons2";
$result = mysql_query($sql) or die("Unable to select from Polygons1");

while ($row = mysql_fetch_array($result, MYSQL_BOTH))
{
$Parish = $row["Parish"];
$Township = $row["Township"];

$sql2 = "SELECT Parish, Township, x, y FROM CheshirePolygons2 WHERE Parish = '{$Parish}' AND Township = '{$Township}' ORDER BY OrderId";
$result2 = mysql_query($sql2) or die("Unable to select from Polygons2");

$i = 0;

unset ($coordinate);
unset ($coordinate2x);
unset ($coordinate2y);

while ($row2 = mysql_fetch_array($result2, MYSQL_BOTH))
{
$coordinate[$i] = (((($row2['x'] - 312822) / 10) / 7.118) + 4) . ',' . (1069 - (((($row2['y'] - 334713) / 10) / 7.116) - 2));
$coordinate2x[$i] = (((($row2['x'] - 312822) / 10) / 7.118) + 4);
$coordinate2y[$i] = (1069 - (((($row2['y'] - 334713) / 10) / 7.116) - 2));

$name = $row2["Township"];
$parish = $row2["Parish"];

$i++;
}

echo "<script type=\"text/javascript\">\n";
echo "<!--\n";
echo " function myDrawFunction()\n";
echo " {\n";
echo " jg_doc.setColor(\"blue\");\n";
echo " jg_doc.drawPolyline(new Array(" . WriteCoordinatesX($coordinate2x) . "), new Array(" . WriteCoordinatesY($coordinate2y) . "));\n";
echo " jg_doc.paint();\n";
echo " }\n";
echo " var jg_doc = new jsGraphics();\n";
echo " var jg = new jsGraphics(\"anotherCanvas\");\n";
echo " myDrawFunction();\n";
echo " </script>\n";

echo " <area HREF=\"view.php?hotspot=$name\" ALT=\"$parish\" TITLE=\"$name\" SHAPE=\"poly\" onmouseover=\"myDrawFunction($name,$parish)\" COORDS=\"" . WriteCoordinates($coordinate) . "\">\n";
mysql_free_result($result2);
}

mysql_free_result($result);

echo " </map>";

function WriteCoordinates($coordinates)
{
$return = "";
for($i = 0; $i < sizeof($coordinates); $i++)
{
$return .= $coordinates[$i];

if($i != (sizeof($coordinates) - 1))
{
$return .= ",";
}
}
return $return;
}

function WriteCoordinatesX($coordinate2x)
{
$return = "";
for($i = 0; $i < sizeof($coordinate2x); $i++)
{
$return .= $coordinate2x[$i] + 5;

if($i != (sizeof($coordinate2x) - 1))
{
$return .= ",";
}
}
return $return;
}

function WriteCoordinatesY($coordinate2y)
{
$return = "";
for($i = 0; $i < sizeof($coordinate2y); $i++)
{
$return .= $coordinate2y[$i] + 6;

if($i != (sizeof($coordinate2y) - 1))
{
$return .= ",";
}
}
return $return;
}

echo " <div>\n";
?>
</body>
</html>
<?php

unset($_SESSION['error_msg']);
?>
[/quote]
Link to comment
Share on other sites
ToonMariner Advanced Member

ToonMariner

Posted
Posted
first thing you can do to make it faster is to change your for loops.

In the declaration of the loop you use sizeof() as the count limit. This is very slow as it is evaluate each time the loop runs.

change it to

$stop = sizeof($cordinates);
for($i = 0; $i < $stop; $i++) {.....

do similar for the other loop.
Link to comment
Share on other sites
AndyB Regular Member

AndyB

Posted
Posted
Use constants not numbers - it's quicker to calculate when a numerical value is pre-assigned to a program 'constant'. For example, changing all the absolute values in a line such as this:
[code]$coordinate[$i] = (((($row2['x'] - 312822) / 10) / 7.118) + 4) . ',' . (1069 - (((($row2['y'] - 334713) / 10) / 7.116) - 2));[/code]
should improve execution speed.
Link to comment
Share on other sites
This thread is more than a year old. Please don't revive it unless you have something important to add.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.